Epoxy Caused Collapse Of 17th Bridge Railing
ATLANTA (AJC)-State transportation officials acknowledged Friday that a type of fast-set epoxy that a federal advisory warned about in 2006 was the same used in the 17th Street Bridge project, a portion of which failed last year when the canopy railing crashed to the Downtown Connector below.
In the 2006 advisory, which came after ceiling tiles fell in a Boston tunnel and killed a motorist, federal officials urged state highway agencies across the nation to retrofit or replace existing projects that used the epoxy under sustained tension. Georgia Department of Transportation officials, however, did not believe the bridge, built in 2004, met that same criteria.
“Obviously, in retrospect, had we known then what we have come to find out, we would’ve gone back and [replaced the epoxy],” DOT spokesman David Spear said.
The epoxy used in the Georgia railing project was used in conjunction with concrete parapets, as opposed to being used in ceiling tiles in the Boston tunnel, Spear said.
The fast-set epoxy will no longer be used in Georgia’s bridge projects, state officials said.
At a news conference in which they detailed the findings of an investigation into the Aug. 13 incident, DOT officials defended the initial construction of the bridge, explaining it was built to industry standard in 2004. The bridge had also been inspected at least twice after officials received the federal advisory regarding fast-set epoxy.
Gerald Ross, the state’s chief engineer, said no evidence of potential failure was observed in the subsequent inspections.
“It’s a difficult thing to see physically, but [inspectors] looked and we never noticed it,” Ross said, explaining that the epoxy was applied within anchor holes. “You can’t determine when [the creeping] occurred. With the loads on it, it could’ve failed the day before or nine months before.”
No one was injured in the incident, which occurred late on a Saturday night and sent a 1-ton metal canopy crashing below.
Mark Moore, principal with WJE, said Friday that a secondary but far less critical component to the railing failure was an unequal mixing and distribution of the epoxy.
Officials said, however, that general contractor C.W. Matthews, which constructed the bridge, is not to blame for the failure and will not be subject to litigation.
“We believe that had those [unequal mixing] conditions not existed, these anchors still would have failed,” Moore said.
Bill Hammack, CEO of C.W. Matthews, could not be immediately reached for comment Friday.
Ross and other DOT officials said they accept responsibility for the ultimate railing failure.
“We were responsible for the inspection of it when it was constructed, responsible for the acceptance of it and responsible for the design of it,” Ross said.
Ross said the DOT is conducting an inventory of the state’s roughly 15,000 bridges and other transportation projects for additional inspection, but he added that the 17th Street Bridge was unique in its cantileverconstruction. No other bridges in Georgia have the same type of canopy railing as used in the 17th Street project.
The DOT also plans to reinforce any other projects that used the epoxy material, beginning with those over roadways, Spear said. Other projects that used the epoxy include sound barriers, state officials said.
C.W. Matthews also built the Fifth Street Bridge, but it is a different construction than the 17th Street Bridge and is not considered at-risk.
The north side of the 17th Street Bridge will be reinforced with additional bolts to create a more secure connection, and the south side of the bridge will be rebuilt with improved and more secure design, Ross said.
“The most positive thing is no one was hurt or injured,” DOT Commissioner Keith Golden said. “It is a lesson learned for us, but it’s a lesson learned for the entire industry.”
Staff writer Ariel Hart and Jon Lewis, a reporter with AM 750 and 95.5FM News/Talk WSB, contributed to this article.